- Preserve exception in case it is lost before it is re-reaised ([commit](https://github.com/miguelgrinberg/python-engineio/commit/f0c2f5b444b57c7b80f262e90fcd608cd3af2deb))
- Added a port of the "latency" example from the official Javascript client ([commit](https://github.com/miguelgrinberg/python-engineio/commit/b976ff304e045aa375ec3f9f1f8f17483b2d1934))
- Allow application to provide a custom JSON encoder/decoder. ([commit](https://github.com/miguelgrinberg/python-engineio/commit/1e8fab676f83eab1b82778ab6dcd362609301d57))